{
 "about": "The record of this Plate: the facts it is drawn from, kept inside the work. Plain JSON; the artwork does not read it. CC0 1.0, no rights reserved.",
 "work": {"title": "Antarctica", "series": "Plates", "artist": "Kenny Lienhard", "year": 2026, "plate": "3 of 52", "palette": "opal"},
 "plate": {"name": "Antarctica", "code": "AN", "model": "PB2002 (Bird 2003)", "class": "major", "area_km2": 58149635, "centroid_lat_lon": [-83.611, 57.8], "ocean_share": 0.7622, "land_share": 0.2378},
 "motion": {"frame": "no-net-rotation", "euler_pole_lat_lon": [62.0639, -117.1268], "rotation_deg_per_million_years": 0.23094, "speed_mm_per_year_at_centroid": 9.44, "heading_deg_at_centroid": 276.5, "speed_range_mm_per_year": [0.0, 25.5], "the_artwork_drifts": "-9.44 mm a year along its cut, one frame of rock every 25655 years"},
 "cover": {"deep ocean": 0.616, "ice": 0.2377, "slope and ridge": 0.1029, "sea ice": 0.0399, "shelf sea": 0.0032, "ocean trench": 0.0001, "bare rock": 0.0001},
 "palette_from": ["ice", "deep ocean", "ocean"],
 "era": {"name": "Glacial sea ice", "what": "Summer sea ice and the ice sheet on the shelf", "arrives_years_before_2026": [30100, 30000], "leaves_years_before_2026": [19076, 11296], "account": "The past. The ice age: sea ice that lasted through the summer covered two to three times today’s area, mostly off the Weddell and Ross seas, and the ice sheet reached out across much of the continental shelf, so a sixth to a quarter of today’s open sea on the plate lay under ice even in summer. The ice was already there when the timeline begins; it drew back roughly 19,076 to 11,296 years ago. The lines that stand for the open sea turn paler, toward ice, all at once, and only across those spans.", "source": "Lhardy et al. 2021, Climate of the Past 17:1139; Crosta et al. 2022, Climate of the Past 18:1729; Bentley et al. 2014, Quaternary Science Reviews 100:1"},
 "history": [{"years_ago": 3900000000, "range_years_ago": [3937000000, 3754000000], "what": "Some of the oldest known rocks on Earth formed, now found in East Antarctica.", "source": "Black, Williams and Compston 1986, Contributions to Mineralogy and Petrology 94:427, doi:10.1007/BF00376336; Hiess and Bennett 2016, Chemical Geology 427:125, doi:10.1016/j.chemgeo.2016.02.011"}, {"years_ago": 182780000, "range_years_ago": [182780000, 182430000], "what": "Huge volumes of magma spread through the crust as the supercontinent Gondwana began to break apart.", "source": "Burgess et al. 2015, Earth and Planetary Science Letters 415:90, doi:10.1016/j.epsl.2015.01.037; Mueller and Jokat 2019, Tectonophysics 750:301, doi:10.1016/j.tecto.2018.11.008"}, {"years_ago": 136000000, "range_years_ago": [136000000, 126000000], "what": "A new ocean ridge began to split India away from Antarctica and Australia.", "source": "Gibbons, Whittaker and Muller 2013, Journal of Geophysical Research 118:808, doi:10.1002/jgrb.50079"}, {"years_ago": 83500000, "range_years_ago": [87675000, 79325000], "what": "After a long rift, Australia broke away from Antarctica.", "source": "Williams, Whittaker and Muller 2011, Tectonics 30:TC6012, doi:10.1029/2011TC002912"}, {"years_ago": 50000000, "range_years_ago": [50000000, 30000000], "what": "South America began to pull away faster from the Antarctic Peninsula, starting to open the Drake Passage.", "source": "Livermore et al. 2005, Earth and Planetary Science Letters 236:459, doi:10.1016/j.epsl.2005.03.027; Eagles and Jokat 2014, Tectonophysics 611:28, doi:10.1016/j.tecto.2013.11.021"}, {"years_ago": 33900000, "range_years_ago": [35595000, 32205000], "what": "Ice sheets spread across Antarctica as the world cooled at the end of the Eocene.", "source": "DeConto and Pollard 2003, Nature 421:245, doi:10.1038/nature01290; ICS International Chronostratigraphic Chart v2024/12 (Cohen et al. 2013, updated), stratigraphy.org"}],
 "outline_lon_lat": [[[-177.93, -65.86], [-180.0, -65.75], [-180.0, -90.0], [180.0, -90.0], [180.0, -65.75], [175.58, -63.98], [173.63, -64.74], [169.24, -62.45], [166.86, -63.22], [165.1, -62.08], [163.2, -62.66], [161.23, -61.46], [156.46, -62.91], [153.64, -59.93], [151.29, -60.41], [150.73, -59.48], [150.01, -59.57], [148.81, -57.44], [147.9, -57.57], [146.88, -54.7], [144.28, -54.8], [140.66, -53.89], [139.65, -50.28], [130.57, -50.52], [127.14, -49.98], [127.31, -48.76], [126.43, -48.63], [125.9, -49.72], [124.21, -48.85], [122.22, -49.85], [120.84, -48.89], [120.27, -50.04], [116.64, -49.27], [114.02, -50.39], [111.67, -50.08], [100.2, -47.27], [99.62, -47.98], [95.84, -46.52], [96.7, -45.47], [85.86, -40.83], [83.44, -42.89], [80.93, -41.13], [79.99, -41.89], [77.82, -40.33], [78.71, -38.0], [78.02, -37.48], [79.18, -36.51], [78.2, -35.68], [78.8, -35.16], [77.35, -33.84], [78.09, -33.19], [76.39, -31.72], [74.41, -28.32], [69.96, -25.65], [67.43, -26.57], [67.13, -27.27], [60.81, -28.93], [60.76, -30.53], [59.19, -30.57], [58.46, -31.69], [57.15, -31.77], [57.06, -33.55], [54.26, -34.54], [53.47, -36.14], [52.34, -36.16], [52.28, -37.43], [46.24, -38.87], [46.07, -40.12], [42.87, -40.85], [42.47, -42.73], [41.81, -42.66], [41.56, -43.58], [39.46, -43.29], [39.07, -44.16], [37.51, -44.88], [35.18, -44.86], [33.17, -47.26], [31.87, -47.2], [28.11, -52.9], [26.71, -52.38], [25.99, -53.58], [18.54, -52.73], [15.82, -51.79], [13.79, -52.48], [12.9, -51.96], [10.97, -53.33], [9.99, -52.79], [7.77, -54.4], [6.63, -53.81], [4.41, -54.43], [3.03, -53.65], [0.96, -54.83], [0.44, -54.45], [-1.61, -55.13], [-1.61, -55.65], [-4.69, -55.81], [-4.69, -56.59], [-6.06, -56.67], [-7.01, -57.87], [-15.97, -58.44], [-16.41, -59.1], [-18.06, -59.15], [-19.58, -60.81], [-32.37, -60.41], [-36.42, -61.39], [-46.96, -59.96], [-50.89, -60.09], [-61.75, -63.29], [-63.97, -62.42], [-56.92, -60.56], [-71.55, -56.26], [-75.72, -53.94], [-77.02, -49.19], [-76.01, -45.66], [-77.66, -45.76], [-78.21, -44.41], [-81.93, -44.96], [-82.51, -42.86], [-83.45, -42.98], [-83.83, -41.12], [-91.39, -41.1], [-91.66, -38.87], [-94.0, -38.48], [-94.13, -37.0], [-108.8, -35.13], [-109.26, -34.54], [-110.83, -35.09], [-110.47, -36.41], [-111.27, -38.98], [-110.39, -38.99], [-110.95, -42.25], [-113.88, -49.85], [-116.39, -49.37], [-118.98, -52.9], [-117.66, -53.12], [-118.58, -54.82], [-120.66, -54.41], [-121.86, -56.03], [-137.89, -53.57], [-140.32, -57.05], [-144.86, -55.78], [-156.72, -63.32], [-162.06, -62.39], [-163.92, -63.47], [-166.61, -62.49], [-170.04, -64.86], [-171.3, -64.36], [-174.42, -65.84], [-175.73, -65.18], [-177.93, -65.86]]],
 "sources": ["Plate outlines and motion: Bird, P. (2003). An updated digital model of plate boundaries. Geochemistry, Geophysics, Geosystems 4(3), 1027, doi:10.1029/2001GC000252. No-net-rotation frame computed from PB2002 alone.", "What covers each plate: ESA CCI Land Cover and Water Bodies, NOAA ETOPO 2022, Koppen-Geiger climate maps, NSIDC Sea Ice Index, on a 1 arc-minute grid."],
 "engine_sha256": "a7fbc03acc0fc9ba343881bb88ddaf2b7564564d8bc9cbed16e75e47e01fb3f2"
}